There are 360 degrees in a circle and the circumference of a circle of radius R is 2piR or
6.282 x radius.

Each degree can be split into 60 parts called a minute

Each minute can be split into 60 seconds called a second

So there are 60x60 seconds in a degree

How many seconds in a circle?

The "arc" or part of a circle made up of a 90 degree angle at the center is
its circumference times 90/360

So for a circle of radius 10metres, its circumference is 6.282 x 10 = 62.82m

For this circle an angle of 1 degree has an arc of (1/360) x 62.82 = 0.175m

An angle of 1 minute at the centre subtends an arc of (1/360x60) x62.82 = 0.003m

An angle of 1 second at the centre subtends an arc of (1/360x60x60) x62.82 = 0.00005m

Latitude measures "angle" at the center of the Earth, so an angle of
90 degrees at the centre corresponds to a distance or arc of 6.282 x Earth's radius x 0.25 km
at the surface.

So the distance between the North Pole and Belem in Brazil (0 degrees latitude) is
6.282 x 6389 x 0.25 = 10033.9km.

Oswego is at latitude 43.455 degrees N, Syracuse is at latitude 43.04 degrees N, a difference
of about 0.42 degrees, so the distance from Syracuse to Oswego is circmference of the Earth x (0.42/360) km.

An arcminute is the length of arc subtended by an angle of a minute at the center.

An arcsecond is the length of arc subtended by an angle of a second at the center.

On Earth, the angular size of the full moon is about 30 minutes of arc.

The angular size of an object is proportional to its linear size divided by its distance from you.